Loom with pneumatic picking means



Feb. 14, 1967 w. SCHEFFEL LOOM WITH PNEUMATIC PICKING MEANS 3 Sheets-Sheet 1 Original Filed Aug. 9, 1963 Jnvenfar: WA LTER SCHEFFEL BY wad ATTORNEY.

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United States Patent 3,303,857 LOOM WITH PNEUMATIC PICKING MEANS Walter Scheifel, 53 Industriestrasse, Weissenburg, Bavaria, Germany Original application Aug. 9, 1963, Ser. No. 301,068, pow Patent No. 3,250,299, dated May 10, 1966. Divided and this application Dec. 8, 1965, Ser. No. 512,302 2 Claims. (Cl. 139-127) This application is a division of Patent No. 3,250,299, issued May 10, 1966.

This invention relates to a loom with pneumatic picking.

The invention has as its main objects to accelerate pneumatic picking of weft threads on appropriate looms and to produce a faste edge on the fabric. To this end, the invention incorporates a device which pre-accelerates the weft thread as it brings it to that edge of the fabric from which the weft is picked. Such an accelerator is described in the patent aforementioned.

Heretofore, the weft has had to be accelerated from a stationary state, at the moment of picking, to reach its picking speed. In the itemized patent, the weft thread was enabled to have practically a full, or a substantial portion of its picking, speed at the commencement of the picking, the weft thread being already picked, when the picking impulse was transmitted. Consequently, it did not first have to be accelerated from a rest state, with the advantage that picking was much more rapid than previously possible. In the therein described embodiment, the accelerator was seen to comprise a tube having Patented Feb. 14, 1967 passed therethrough, the picked portion of the weft thread was separated from the remainder of the weft thread by the thread cutter.

To ensure that a weft thread portion of a specific length was drawn off and measured, the surface of at least one of the rollers was adapted to yield, with respect to the Y other roller, at the point where the thread draw-01f was a looped, ringlike portion through which compressed air flowed and characterized by a continuous slot towards the area enclosed by the loop or ring. The compressed air, continuously flowing in the tube, engaged the weft thread at the entry point and blew it through the tube, so that, on the one hand, it was drawn off the feed bobbin, and on the other hand, it reached the tube exit, there being means to ensure that the picking of the weft thread commenced when the free end of the weft thread was situated at the exit from the tube and a control system to ensure that the thread brake was closed as soon as the free weft thread end was at the tube exit. The compressed air caused the weft thread to fly through the tube exit as the loop formed by the weft thread inside the crossed annular tube was pulled open. As soon as the weft thread had been picked, a thread cutter cut the picked portion of the weft thread from the remainder thereof and the weft thread portion situated in the exit section of the tube was returned to the entry section by a suitable thread returner. After the weft thread had been cut and the required length had been measured off, the weft thread was returned by a pair of rotating rollers, the surfaces of which contacted one another and between which surfaces the weft thread extended from the feed bobbin to the slotted tube, at least one of the rollers governing the length of the weft thread to be drawn off. A thread brake, controlled in dependence on the peripheral travel of the rollers, was opened at the beginning of the weft thread storage program and closed at the end thereof. Practically the entire interval between two weft thread picking operations was utilized for drawing off and measuring a length of weft thread. During drawing off, the weft thread was paid out inside the slotted tube as a result of the continuous injection of compressed air thereinto. After the required length of weft thread had been measured and stored in the slotted tube, the brake was closed. A new shed was formed with the closing of the thread brake so that the beginning of the weft thread, which left the slotted tube with preacceleration immediately after closure of the thread brake, could enter the shed, and as soon as it had to terminate, by an amount at least such as to prevent any entrainment of thread.

After a weft thread had been picked and cut off at the tube exit end, the cut weft thread had to return from the exit to the entry end of the tube so as to ensure storage of the next weft thread portion in the tube, and to this end, an externally projecting cam was provided on the surface of one roller and a recess complementing the cam was provided on the other roller.

The present invention consists in the specific construction of the weft picking device and in its use. When a non-slotted tube is connected to the slotted tube, and when the non-slotted tube has a beginning which faces the feed bobbin, the total length of the slotted tube may coincide in the same way as the total length of the nonslotted tube with the length of a weft thread portion of actual weaving width. Such a slotted tube with a non slotted tube may be disposed on each side of the fabric to be formed, with a thread cutter being provided at the entrance end of the two tube-s and with, at each side of the fabric to be formed, a roller element for determining the length of a weft thread of double the weaving width to be drawn off and constructed as a semicircular disc opposite a pressure roller, all whereby the length of the half are coincides with the length of the thread portion of double the weaving width to be drawn off, the semi-circular discs being offset angularly by with respect to each other.

By this construction, after the storage of a weft thread of double the weaving width at one edge of the fabric, and after the picking of the weft thread of the length of the actual weaving width from the same side, the picking of a weft thread may take place at the other edge of the fabric. There following, the part of the initially picked weft thread left in the slotted tube and in the non-slotted tube is cut through by means of a cutter, and picked, after which the same procedure takes place from the opposite side.

With such system, weft thread portions of twice the weaving width are paid out in a storage tube during the measuring process. If the thread brake belonging to the storage tube is then closed, the thread portions stored in the slotted tube part are stretched and picked. After the weft thread has been beaten up and another shed formed, a weft thread i picked in the new shed from the other side of the fabric in the same way. This new weft thread is also then beaten up, whereupon the weft thread, of the length of the actual weaving width left in the storage tube at the initial picking side, is 'cut off so that the compressed air entering the storage tube picks the cut weft thread portion in another new shed. The procedure is thereupon repeated, but from the other side.

Further advantages and features are explained in the following description of the drawings which illustrate earlier embodiments of the invention as well as the present embodiment and wherein:

FIG. 1 diagrammatically illustrates a weft thread accelerator to show its general principles;

FIG. 2 diagrammatically illustrates the timing of the drawing off and picking by means of the FIG. 1 device;

FIG. 3 is a section on line III-III of FIG. 1;

FIG. 4 is a section on line IVIV of FIG. 1;

FIG. 5 shows a modified form of the FIG. 1 device for purposes of illustration;

able construction of the roller element surface;

FIG. 8 shows the operation of the form of the device of the present invention, same exemplifying a two-fold arrangement for producing fixed edges at the fabric; and

FIG. 9 shows the position of the weft thread for double Weft thread picking from the edges.

In the FIGS. 1 to 4 embodiment, the accelerator consists essentially of an annular tube 1 and a thread brake 2, the tube being connected to a compressed air pipe 3 into which air flows continuously in the direction of arrow A. The outer free end portion 1 of tube 1 crosses the inner free end portion 1 to provide an intermediate slotted looped portion. From a feed bobbin 5, a weft thread F passes through brake 2 and enters tube 1 at 6. The beginning of the weft thread, which initially only enters tube 1, is engaged by the continuous flow of air and is paid out inside the tube to the exit point thereof at the outer end of free end portion 1. The enclosed area defined by the loop is covered by spaced end plates 8 and 9 defining a duct 12 therebetween.

When brake 2 is closed, as soon as the tip of the weft thread reaches the exit point at the outer end of free end portion 1', the Weft thread continues to move in the direction of arrow E. The loop which it has formed inside tube 1 is pulled open as it passes through the slot 7 of the loop and duct 12. When the loop has been pulled open, the weft thread extends directly from the beginning of inner free end portion 1" to outer free end portion 1' of tube 1.

A photoelectric cell 13 on tube 1 control brake 2. Each paid out portion of the weft thread passes therepast so that when the weft thread arrives, the closure of brake 2 is signalled.

Photoelectric cell 13 is adjustable so as to function in opposition to the direction of arrow P wherefor the precise length of the portion of Weft thread to be picked can be determined and the accelerator can thus be used as a measuring device.

After a Weft thread has been picked, the picked portion of thread is separated from the rest of the weft thread by a thread cutter 14. The weft thread portion in end portion 1 is then pulled into tube 1 by a thread returner in the form of a lever 16 mounted for pivoting at and having a free end 17 engaging the portion of the weft thread and pulling it into tube 1 on movement from the FIG. 1 solid-line position to the FIG. 1 broken-line position.

Other air supply pipes 18, 19 and 20 transmit an air pulse at the moment of picking. These may be connected to the same compressed air source as pipe 3 so that the pressure inside the accelerator closes the valve at the moment of picking and all the air pressure available is then utilized solely for picking the weft thread.

A crankshaft 21 is rotatable in the direction of arrow G. As soon as it reaches point a, brake 2 is opened so that the weft thread is drawn off feed bobbin 5 and is paid out inside tube 1. When pin 22 reaches b, brake 2 is closed. The weft thread, in the meantime, has reached the exit point and is picked while pin 22 reaches point 0. While pin 22 moves from c to d, the picked thread is beaten up and cut off. When pin 22 reaches d, thread returner 16 begins to withdraw the remainder of the thread from tube end 1. The return operation is completed as soon as pin 22 reaches a.

The device also serves as a measuring device. To enable a required length of weft thread to be selected and determined, at least one limiting means 24 is provided to vary the length of slot 7 and is slidable so as to cover the slot at the place to which it has been slit. The total length of the free slot can be varied and finely adjusted,

even during operation. The movability of photoelectric cell 13 is intended only for adjustment of its distance from the said exit point C so that the beginning of the weft thread precisely reaches the exit point C Within the interval between the transmission of the pulse by photoelectric cell 13 and the actuation of brake 2.

In the FIGS. 5 to 7 embodiment, a weft thread S is drawn from a feed bobbin 33 by means of rollers 31 and 32. The thread enters a storage tube 35 via an inlet tube 34, a thread cutter 37 being disposed after an exit point 36. Rollers 31 and 32, of discoid construction, contact one another over an arc corresponding to the length of the weft thread to be measured. The Weft thread itself passes betwen the rollers so that, during rotation of the latter according to arrows A and B, the Weft thread is entrained by contact between said elements. There is contact, over an are C, between the rollers, said arc extending from point D to E on roller 32. The contact on roller 31 extends from D10 to E10. A thread brake 38, preceding the rollers, is controlled by a cam disc 39 which rotates in synchronism with roller 32, being rigidly connected thereto. A double lever 40 cooperates With the cam and at its free ends bears a roller 41 hearing against the control cam, said lever being fixed at 42 while its other end actuates brake 38 directly via a rod 43. Roller 32 has a smaller diameter over are F than over are C so that when it moves with its surface along arc F in relation to roller 31, the weft thread is not transported. As soon as cam 44 on roller 31 enters a recess 45, the weft thread is Withdrawn. On rotation of the rollers, brake 38 is opened by cam 39 as soon as the points D, D10 contact one another. Weft thread S is consequently drawn from feed bobbin 33 and is paid out in storage tube 35. As soon as the rollers have rolled on one another to the extent that they contact one another at points E and E10, the beginning of the weft thread reaches exit point 36. At the next moment, contact between the rollers is terminated, since roller 32 yields to a smaller diameter at point B. Cam 39, at the same time, closes the thread brake so that the weft thread portion paid out in storage tube 35 leaves the latter through the slot and its beginning 46 leaves storage tube exit 36. The thread is brought into a stretched position inside the storage tube from its looped position. The individual movements of the associated loom and of the apparatus are such that, on the closure of brake 38, a new shed is ready opposite exit 36. The weft thread leaving the storage tube enters this shed and is separated from the rest of the weft thread by cutter 37.

After contact at E and E10 has been discontinued, rollers 31 and 32 continue to move in the direction of arrows A and B. The weft thread is not transported, and brake 38 is closed. Cam 44 finally reaches recess 45, enters the latter, and then leaves it. When brake 38 is closed, weft thread S is pushed into recess 45 so that the weft thread end still remaining in storage tube 35 is withdrawn from exit tube 36 to level 46. On further rotation of rollers 31 and 32, they finally contact one another again at points D, D10, brake 38 being simultaneously opened by control cam 39 so that a weft thread portion, of a length corresponding to are C, is again drawn from feed bobbin 33 and paid out in storage tube 35. The process then repeats itself.

Air is supplied to storage tube 35 via a blower pipe 47 and a pump pipe 48. That the weft thread to be stored does not leave the slot during storage, it is subjected to suction via two Venturi intake nozzles 49 and 50. Air reaching nozzle 50 is fed via pipe 51 from pipe 47, while air reaching nozzle 49 is fed from pipe 47 via pipe 52. Pipe 52 also contains a rotary valve 53 which can be mechanically adjusted via a lever 54 and which meters the air coming from the blower to the quantity required for storage in storage tube 35.

The surfaces of rollers 31 and 32 are resilient, at least over the zone where there is contact between the discs. A thin sheet steel cylinder 57, 58 forming the outer surface may be applied to the solid roller elements of cores 31a and 32a respectively, the cylinders being borne by springs 59 with respect to the cores.

And now with specific reference to the present invention.

To produce a fast edge, a measuring and accelerator device is provided at each edge of the fabric having the construction shown by way of example in FIG. 8. In this case, a roller 60 governing the length of a weft thread S1 is constructed as a semi-circular disc, with a diameter such that the surface length over the arc G coincides with twice the weaving width W.

The roller is driven by a shaft 61 in the direction of the arrow H. Roller 62 cooperates therewith and comes into contact with it as soon as the edge I has moved to K. From that moment on, the weft thread running through a brake 63 is transported to a storage tube 64, whose length is such that it can accommodate a portion of thread equal to twice weaving width W.

Storage tube 64 has a slotted part 65 and a nonslotted part 66. The slotted part begins at the exit end 67. The length of the slot coincides with actual weaving width W. That is, the total length of the slotted tube coincides in the same way as the total length of the non-slotted tube with the length of a weft thread portion of the actual weaving width. A cutter 68 is provided at the storage tube entry.

The device illustrated at the left-hand side of the drawing is the same as that on the right-hand side thereof, rollers 60 and 60a being offset angularly by 90 degrees with respect to each other.

As soon as edge I reaches point K and brake 63 has opened, weft thread S1 is transported to storage tube 64. Here it is paid out inside the tube by compressed air flowing through pipes 69 and 70. As soon as edge L leaves point K, the beginning of the thread reaches the level M. At that moment, brake 63 is closed. Consequently, the weft thread portion in the slotted part of the tube is compelled to leave the slot and to enter the new shed.

The weft thread which has just been picked from the right-hand device is referenced as S2. After the picking of this weft thread, it is beaten up, whereupon a weft thread S3 is then inserted into the next shed from the left-hand side. As soon as this weft thread has been beaten up and a new shed has been formed, the portion of the weft thread still remaining in the storage tube is cut off by cutter 68. This portion is therefore engaged by the compressed air from pipes 69 and 70 and is picked in the new shed as shown by the broken line S4. The procedure is similar from the left.

The second part of the weft thread portion of twice the weaving width is folded around the fabric at the edges so as to form a fast edge.

Roller elements 60, 60a are offset in respect of their angular positions so that the weft thread picking is alternately from the right and the left. The arrangement of the angles of the roller elements 60, 60a with respect to one another and the control of the other parts may alternatively be such that two weft threads are picked consecutively from one side of the fabric, as shown in FIG. 9.

The advantage of the measuring devices described is that the measuring operation begins at a time when the shed into which the weft is to be picked has not yet been formed. There is, therefore, relatively considerable time available for the measurement, because the thread is initially stored in the storage tube. The draw-off speed can thus be kept relatively low. This protects the material and enables waste yarns or other yarns having low tearing strength to be used.

In the FIGS. 5 and 6 embodiment, the measurement takes place during an interval greater than the interval required for 200 of a revolution. The interval avail* able for an actual picking operation is below the time required for of a revolution.

The relatively slow rotation of the roller elements means that there is much less risk of slip than with high- .speed rollers. The use of a steel band to form the roller surface has the advantage that the smooth surface prevents any adhesion of the weft thread as it runs off the surface.

In the embodiment according to FIG. 8, the weft thread no longer has to be withdrawn.

I claim:

1. In a loom with pneumatic weft picking, the combination of, a storage tube comprising a slotted tube and a non-slotted tube on each side of a fabric being formed, the slotted and non-slotted tubes of each pair being interconnected and having a beginning facing the feed bob bin in manner whereby the total length of the slotted tube coincides in the same way as the total length of the non-slotted tube with the length of the weft thread portion of the actual weaving width, a thread cutter at the entrance end of each said storage tube, a semicircular roller disposed at each side of the fabric being formed for determining the length of a weft thread of double the weaving width to be drawn off, a pressure roller disposed opposite each said roller, the length of the half are of said roller coinciding with the length of the thread portion of double the weaving width to be drawn off, the semicircular rollers of the pair being offset angularly by 90 degrees with respect to each other.

2. In the loom as set forth in claim 1, characterized in the respect that following storage of a weft thread of double the weaving width at one side of the fabric being formed after the picking of the weft thread of the length of the actual weaving width from the same side, the picking of a weft thread takes place at the other side and in the respect that therefollowing the part of the initially picked weft thread left in the slotted tube and in the storage tube is cut through by means of the thread cutter and picked after which the same procedure takes place from the opposite side.

References Cited by the Examiner UNITED STATES PATENTS 1,096,283 5/1914 Brooks 139-127 1,164,959 12/1915 Potstada 139-127 2,662,556 12/1953 Svaty 139-127 3,024,814 3/1962 TeStrake 139-127 3,140,633 7/1964 Vincent 139127 3,181,571 5/1965 Schelfel 139127 FOREIGN PATENTS 174,387 2/1961 Sweden.

1,261,463 4/1961 France.

MERVIN STEIN, Primary Examiner.

J. KEE CHI, Assistant Examiner. 

1. IN A LOOM WITH PNEUMATIC WEFT PICKING, THE COMBINATION OF, A STORAGE TUBE COMPRISING A SLOTTED TUBE AND A NON-SLOTTED TUBE ON EACH SIDE OF A FABRIC BEING FORMED, THE SLOTTED AND NON-SLOTTED TUBES OF EACH PAIR BEING INTERCONNECTED AND HAVING A BEGINNING FACING THE FEED BOBBIN IN MANNER WHEREBY THE TOTAL LENGTH OF THE SLOTTED TUBE COINCIDES IN THE SAME WAY AS THE TOTAL LENGTH OF THE NON-SLOTTED TUBE WITH THE LENGTH OF THE WEFT THREAD PORTION OF THE ACTUAL WEAVING WIDTH, A THREAD CUTTER AT THE ENTRANCE END OF EACH SAID STORAGE TUBE, A SEMICIRCULAR ROLLER DISPOSED AT EACH SIDE OF THE FABRIC BEING FORMED FOR DETERMINING THE LENGTH OF A WEFT THREAD OF DOUBLE THE WEAVING WIDTH TO BE DRAWN OFF, A PRESSURE ROLLER DISPOSED OPPOSITE EACH SAID ROLLER, THE LENGTH OF THE HALF ARC OF SAID ROLLER COINCIDING WITH THE LENGTH OF THE THREAD PORTION OF DOUBLE THE WEAVING WIDTH TO BE DRAWN OFF, THE SEMICIRCULAR ROLLERS OF THE PAIR BEING OFFSET ANGULARLY BY 90 DEGREES WITH RESPECT TO EACH OTHER. 